‘Black Mirror’ USS Callister Sequel Ending Explained By Stars

The seventh season of “Black Mirror” re-visits one of the series’ most beloved episodes: “USS Callister.”

The Season 4 movie-length episode, which came out in 2017, follows a group of people on what appears to be a space ship. But things are not as they seem. 

It turns out the captain, Robert Daly (a not-so-friendly Jesse Plemons) had cloned his workplace and kept his colleagues captive within a video game. By the end of the episode, Daly met his (well-deserved) end, the crew was finally free. The “Infinity” game’s universe was at their disposal.

Now, almost a decade later, we’re back for a new adventure. Here’s what happens and what stars Cristin Milioti and Jimmi Simpson have to say about where the episode takes them.

What have the clones been up to since ‘USS Callister’?

Taking place a few months after the events of the original Season 4 episode, we learn that the “Infinity” clones are now mercenaries, robbing random players for credit sticks to (illegally) survive inside the game.

“It’s 30 million players versus the five of us,” clone Nanette (Milioti) points out.

Their strategy is soon upended when the players they robbed file a complaint on the game’s forum for two players participating in-game cheating by having no player tags.

On the outside, real Dudani (Paul G. Raymond) urges Walton (Simpson) to address the in-game robberies, since it’s not the first time a complaint has been filed. Walton ignores him, leading Dudani to quit on the spot.

Meanwhile, a New York Times journalist visits Walton under the guise of writing a profile, but it’s really a ruse to get him to talk about the banned DNA digital cloner that was found after Daly’s death and the possibility of the rogue players being illegal clones. Walton kicks him out — but not before Nanette hears the entire conversation.

Real Nanette takes the opportunity to help a visibly shaken Walton to ID the rogue players and discovers they’re the clones of herself and Nate (Osy Ikhile).

What happens after the clones’ existence is revealed?

Inside the Callister, clone Karl (Billy Magnussen) throws out the idea of flying back into Daly’s private game build. And though it seems improbable, it’s not impossible.

“If we can access the game’s source code, we can compile a private development build of a whole universe of our own,” clone Nanette says. “There’d be no more credits, no more other players, no more threats. It would just be us, and we’d be safe.”

The only problem? The only people who could access the source code, Daly and clone Walton, are dead. Or so they think.

Clone Walton has a room aboard the Callister, which should not have spawned since he died before the ship reset itself and the rooms are assigned to players who are alive. Clone Nanette and Dudani believe that a small part of Walton must have survived, so he’s alive in the game on a planet that spawned at the same time he died. Real Nanette has the same idea. She and real Walton enter the game.

Clone Nanette finds clone Walton and they both bump into the real versions of themselves and decide to work together to free the clones.

Aboard the ship, while the “Heart of Infinity” plan is being discussed, real Walton takes this opportunity to betray the crew and prevent the clones’ existence from getting out, shooting and killing clone Karl in the process.

Real Walton and Nanette exit the game, getting into a scuffle outside about deleting the clones. Walton tries to bribe Nanette to continue to help him, but as she is telling him off, she walks into the street, getting hit by a car.

Walton leaves Nanette injured, taking her bag and the evidence with him.

Inside the Callister, clone Walton lets them know that before they can attempt to go into “The Heart of Infinity,” they need to know the truth.

The twist? The “Heart of Infinity” isn’t just the source code — it’s a copy of Daly’s consciousness.

Wait, the ‘Heart of Infinity’ is what? Twist explained

Yes, you read that right.

Twelve years ago, while looking for investments, Walton received a tip about a project Daly had been developing. 

Walton was immediately sold after testing said project. It wasn’t a game but an immersive experience meant to mimic his favorite show “Space Fleet.” Walton, thinking only about profits, convinced Daly to forgo his original plans and pivot to an multiplayer online game and subscription model.

Falling behind their deadline, Walton had the idea to use the same illegal DNA cloner to create a duplicate of Daly and fuse his consciousness with the game’s engine so he could continually build the “Infinity” universe.

What happens between Nanette and Daly in the ‘Heart of Infinity’?

After realizing that real Walton is worried because the literal core of “Infinity” is illegal, clone Nanette tries to warn real Nanette. Clone Nanette is sadly too late, as her outside self is in coma, essentially brain dead after the accident. The accident comes as a shock to clone Nanette, but they continue on their journey to the Heart of Infinity.

Back with the crew, the Callister has arrived to the Heart and clone Nanette is teleported to the core, which is an exact recreation of Daly’s neighborhood.

Clone Nanette finds clone Daly in the garage and explains the entire situation to him, hoping he would help them.

After clone Nanette finishes her story, clone Daly is grappling with the fact that his real self was a vile person, and that Walton exploited his talents.

He agrees to help clone Nanette, but gives her a choice aside from simply leaving. Clone Daly explains that he can transfer her consciousness through the machine real Nanette is hooked up to. The catch? She can only choose one: go back to her old life, but the ship and the crew is wiped, or go with the original plan and save them all.

Clone Nanette chooses to save them all, and clone Daly reveals there was always a choice to do them both; it was just a test of nobility based on an episode of “Space Fleet.” Clone Daly begins the universe transfer, but he wants to “copy and paste” instead of “cut and paste” so another copy of clone Nanette could stay with him.

“I will let her stay. I will treat her good,” clone Daly insists.

Clone Nanette objects, sending clone Daly into a rage and hurting her. Clone Nanette is able to save herself by killing clone Daly, but this activates a kill switch to the delete the game.

Clone Nanette is thankfully able to complete transfer in the eleventh hour. “Infinity” is deleted, and Walton watches his company crash in real time.

What happens to the Callister crew? What about Walton?

Clone Nanette wakes up in the hospital in the body of real Nanette and is over the moon. She then receives a call from the Callister crew and they let her know there were saved — but they’re also part of her consciousness and they can see what she’s seeing. 

Three months later, Walton is arrested and charged after being on the run. We see Nanette indulging in his downfall with the rest of the Callister crew while working on a way to figure out extracting the crew from her consciousness and enjoying binging the crew’s favorite show: “The Real Housewives of Atlanta.”

How did the stars feel about the twist?

Milioti says that twist with Walton and Daly actually didn’t come as a shock to her.

“It felt (timely) that someone would be sentenced to the disease of capitalism. ‘You must be productive of all costs,’ but at the cost of your life,” Milioti says. “It felt true for those characters. You would understand why it would drive Daly mad and it’s something that Walton would completely do.”

The biggest twist for Milioti was actually Nanette’s accident.

“I remember reading that like, ‘Wow that is incredible’,” she says. “I never saw it . It happens so fast.”

How did they feel about the ending?

Milioti loves the “twisted and unexpected” ending for Nanette.

“I thought it was so demented and unexpected and strange and funny,” she says. “It somehow enters us into a new genre of body possession comedy.”  

Simpson he was surprised that they went in that direction, but that “it seemed like the only way.”

“When you’re going to explore a world like this, it’s not just figuring out how to make a fun spot for people to enjoy the characters they love,” he says. “It’s about creating a reason for them to need to get to know them more. Now the sequel is essential viewing.”

Simpson is also satisfied with the downfall of his character.

“Real world Walton needed to go down in a big way. And that was important because we don’t see that too much in real life,” he says.

Will there be more to the Callister crew’s story?

“There’s a cracked door for sure,” Milioti says.

“I think Charlie (Brooker), his mind, can go in 20 million different directions and I’m sure if he wants to continue it, the idea would be very strange and cool and creepy and funny,” she says.

Simpson shared a similar sentiment.

“I feel like there’s so many ways they could go,” he says. “Ultimately, it’s like the rest of Black Mirror. It’s about the writing, it’s about finding the truth in what’s so extraordinary. So I know if that were to happen again, Charlie would follow his instincts and I know everyone in the cast and crew would join in.”